Comet C/2023 A3 Tsuchinshan-ATLAS (Nine Nights of Observing)

Location:  Lower Westside Saint John & Prince of Wales, NB, Canada

Date Time:  October 16, 2024 1940 - 2010hrs

                     October 17, 2024  2020 - 2200hrs

                     October 19, 2024  1935 - 2050 hrs

                     October 20, 2024  1930 - 2110hrs

                     October 22, 2024 1930 - 2050hrs

                     October 25, 2024 1935 - 2030hrs

                     October 29, 2024 1920 - 2020hrs

                     November 2, 2024 1910- 2020hrs

                     November 10, 2024 1915-1930hrs

Weather: Oct 16-Winds from the west, approximately 35km/hr, mostly clear with some passing clouds, very cool, 5.2C 64% humidity. Windchill.

Oct 17-  No wind, mostly clear but hazy, warm, 6.1C with 69% humidity.

Oct 19 - No wind to some breeze, hazy, warm 11C with 64% humidity.

Oct 20 - No wind, hazy at times, warm with some bugs at first, but it cooled off later, 10.6C with 76% humidity.

Oct 22 - No wind, to slight breeze, hazy in places, warm, no bugs, 10.2C with 81% humidity.

Oct 25 - No wind, hazy, no bugs, very cool, 7C with 71% humidity.

Oct 29 - No wind, hazy light fog, very cool, 2C with wind-chill of -2C and 55% humidity.

Nov 2 - Clear, breezy, 25km/hr winds from the north west, very cold, 1.6C with reported wind-chill of -2C & 66% humidity.

Nov 10 - Mostly cloudy, no wind.  Clouds took over much of the sky shortly after we arrived.  See-through clouds moving north west to south, as lead up to an approaching rainstorm.  Earlier forecast reported rain for this time, but the storm front must have moved slower than anticipated. Temps were 1C with windchill and 75% humidity with barometric pressure dropping.

Equipment:  Oct 16, 20, 22, 25, 29, Nov 2 & 10th - Canon Rebel with 18-55 & 75-300mm lenses.  Binoculars.  Images processed on PhotoShop.

Oct 17 & 19 - Canon Rebel with 18-55mm lens and attached to 80mm apo telescope. Binoculars.  Images processed on PhotoShop.

Objective:  To view and image Comet 2023 A3 Atlas-Tsuchinshan.  Here is a star chart, comet path map.

Report:  Oct16 in SJ

• Very windy and cold.  Almost immediately found comet in binos.  It was higher in sky than I thought, but showed up bright with its huge long, needle-like tail that's approximately 5 degrees long(estimate from local observers Curt & Ed seems to be in agreement at 5 degrees).  Long exposure images shows tail to be much longer though. It's an awesome sight! Whitish color, with bright nucleus.  
• Many images were ruined because of the wind, and a huge, strange looking cloud with a dark center in it passed in front of Moon as I was attempting to image it.
• After taking images of comet for a few minutes, the tail started to show up naked eye with averted vision at approximately 1950hrs, looking like a contrail.  Shortly after this it was clearly visible naked eye, albeit faint.  Imo, brighter than Messier 31, the Andromeda Galaxy(magnitude 3.3) .  Brighter than M31 only because it could be seen naked eye from inside the city with a nearly full Moon,  Comet showed up like M31 does under dark skies. I would estimate comet brightness at magnitude 2.5.  
• There was bright, almost full Moon rising in the East that shone like a huge spotlight.

With 18-55 lens.

With 75-300mm lens

Through clouds.

Oct 17 in SJ

• I was not able to get the comet naked eye on this night, possibly because of the brighter full moon or because of hazy sky conditions.  Others, locally(4ppl in 2 different locations) are reporting that they seen it naked eye before 2000 hrs.
• Comet was higher than reported by 5 degrees.  It was reported to be declination 1 degree, but I ended up finding it on my own at declination 6 degrees, which is a very rare mistake, in my experience. 
• Comet was next to Unukalhai, Alpha Serpentis(mag 2.63). Unukalhai is Arabic for "Neck of the Serpent."   
• The comet did pop out easily in binoculars.  Imo, the comets tail seemed much more faint than the night before.  Probably because of sky conditions from my location.  Comet went down below the horizon about 2125hrs.
• Imaged Alkaid, a star in Ursa Major.  Magnitude 1.86. 
• The full moon was super bright, high in the eastern sky.

Alkaid, Magnitude 1.86.  Image 30s, ISO 100 through telescope.

Comet located in Serpens, next to Unukalhai, Alpha Serpentis.  Image was taken with 18-55mm lens, 30s, ISO 100.  Single shot. 

Comet through telescope. 30s, ISO 100.

Full Hunter's Super Moon.

Oct 19 in POW

• Got there early, before dark to try to get comet before the bright, 91% illuminated waning gibbous moon rose and washes out the barely naked eye comet.  Once it got completely dark, the comet was naked eye bright, approximately Mag 3, enough to be able to see directly to find in telescope and binos without having to star hop.
• Comet was massive and very bright in binoculars, a truly wonderful sight.  Through the binos, I could easily see two stars through the comets tail, which was an amazing thing to see.  
• Once the moon rose at around 2030 hrs, the comet was no longer naked eye bright  It was not even visible with averted vision and I could just barely find it in binoculars.  It was shocking how much the comet was washed out by the moon.  Most of its tail was no longer visible in the binoculars field of view and even the nucleus was a small fraction of what it was before the moon interfered.
• Halfway through observing a local person stopped and spoke to me about how long people from SJAC have been using that site for observing, how much the trees have grown up, and that there was a bear around the area causing issues.  

Comet through telescope, before moon rise.  30s ISO 1600 

Comet just before moon rise 2027hrs.  25s ISO 1600

Waning Gibbous Moon 91% illuminated at 2034 hrs.

Oct 20 in Prince of Wales with Ed.

• It got dark enough to see comet naked eye at approximately 1940hrs.  Spectacular comet that's tail is way too long to fit in binocular field of view.  Images had to be taken with a short focal length to get whole tail into frame.  Ed and I guessed at approximately 8 degree long tail with naked eye and agreed that tail is probably much longer than what we can see naked eye.

Image taken at 2006hrs Focal length 75mm, 10sec, ISO 6400.  Inverted. Sun directed anti-tail can clearly be seen in this image.

• Halfway through observing Ed and I observed what we thought was an Orionid meteor, in the Eastern sky, bright, orangish/reddish fast, coming from approximately Orion's direction, which wasn't up yet.  The Orionids peak today, but the brightening moon will not help.  Note:  Someone on Facebook noticed "a bright fireball" at 8pm, at the same about the same time.
• Ed mentioned that M31 Andromeda Galaxy was up in the north eastern sky and so we both viewed it with our binoculars for a brightness/size comparison with the comet.  We both think the comet is much brighter than M31, even though the moon may have affected M31 in my side by side comparison image.

M31/comet comparison image.  Camera settings the same for both.  Focal length 55mm, 32sec, ISO 1600.

• Moon was just starting to rise in the East when we left at 2110hrs.

Oct 22 POW nature trail parking lot.

• Benson, Ed and I were happy to see Curt at location.  Shortly after arriving we all confirmed seeing the comet naked eye.  Benson remarked that "it looked like a line in the sky".  Great description!  That's exactly what it looks like.  Through binoculars Benson thought he could see greenish color.  To me it looks more like a dirty whitish color.  This was Benson's first comet.
• Ed and I thought the comet held about the same brightness as two nights before.  It's still a little brighter than M31.
• I seen a shooting star about halfway through observing low in the northwest, to the west of Ursa Major.
• Ed observed the Double Cluster.

focal length 55mm, 21sec, f/5.6, ISO 6400

focal length 80mm, f/4.0, 10sec, ISO 6400

Same as above.  Inverted.

M31 vs Comet for brightness.  Camera settings are the same.  focal length 80mm, 21sec, f/4.0, ISO 6400

Oct 25 from POW parking lot

• Ed and I arrived just as it was starting to get dark.  Shortly after, we were able to find the comet in binoculars and we both agreed that the comet has dimmed some.  It's now about equal in brightness to M31 (mag 3.4), imo, although Ed thinks comet is a little dimmer than M31.
• The comet is still naked eye bright, but we think that it's only visible because we were in remarkably dark skies.  Probably not visible from light polluted skies like a cities.
• By 2000 hrs the skies were very dark.  I could see five stars in the square of Pegasus, which it is said to mean a limiting factor of mag 5.  Very good viewing conditions except for some haziness.  It was so dark, with only stars showing making it difficult to focus my short lenses.
• Ed and I both noticed many satellites and a number of shooting stars.  All of the shooting stars were heading in the western direction.  The one that I seen was high in the southern sky, streaked over Delphinus heading towards the comet, at about 2036hrs.
• Ed remarked about Cassiopeia which was nicely placed for viewing in the north eastern sky.
• Comet has some kind of star cluster in the tail and is in images.  When I determine its identity I will update this post.  The cluster showed up nicely in binos as well.

Comet vs M31 brightness comparison images.  Camera settings were the same. Single shot, focal length 55mm, 21seconds, f/5.6, ISO 6400

Comet approaching IC 4665. Same settings as above.

Single shot, focal length 180mm, 4sec, f/5.0, ISO 6400.

Same settings as above, inverted.

Oct 29 at POW Nature Trail parking lot

• Ed and I arrived around 1920 hours, but complete darkness not until about 1950 hours. For the first time, the comet was not visible to the naked eye, although M31 was still observable, indicating that the comet has significantly dimmed as it travels away from Earth into deeper space. The comet was clearly visible through binoculars, positioned near a bright star and adjacent to one of the numerous open clusters in Ophiuchus, appearing much smaller and fainter within the binoculars' field of view than on previous nights.  The comet dimmed so much that I had difficulty finding it in binoculars.

settings the same for both images. 155mm, 10sec, f/5.0, ISO 6400

150mm, 6.2sec, f/5.0, ISO 6400

Comet and IC 4665.  150mm, 4sec, f/5.0, ISO 6400

• While scanning the skies for the comet with my binoculars, I chanced upon one of my favorite sights for binoculars or a small telescope: The Coat Hanger asterism, also known as Brocchi's Cluster. It's fascinating how a simple collection of stars can arrange themselves into a shape that's so easily recognizable.

150mm, 4sec, f/5.0, ISO 6400

Nov 2 from nature trail parking lot in POW

• The comet may no longer be visible to the naked eye, yet it remains a splendid sight through binoculars, albeit smaller and fainter than before. It's situated in the star-rich Ophiuchus constellation and has drifted past the second brightest Ophiuchus star, Cebalrai(Arabic for Heart of the Shepard) and IC 4665 open cluster, which still appears in many of my wide-angle images. This star and cluster also serves as an excellent reference points for locating the comet with binoculars. Each night, the comet slowly recedes from Earth, shifting upward and slightly to the left. The extremely dark skies provide an ideal backdrop, although the windy and cold conditions pose challenges for imaging.

Cebalrai & IC4665 are bottom center. The famed, 9th magnitude Barnard's Star is very close to where the comet in this image. It's one of the closest stars to Earth. 75mm, 6.2sec, f/4.0, ISO 6400.

Comet size/brightness comparison from 20 Oct to 2 Nov.

Comet passing near IC 4665 (lower right) 75mm, 10sec, f/4.0, ISO 6400

Comet vs M31 for brightness/size comparison.  75mm, 10sec, f/4.0, ISO 6400

Zoomed in 250mm, 2.5sec, f/5.6, ISO 6400

• I used bright star Alpha Aurigae, Capella(the Goat Star) to focus my camera on. The star, which is one of the brightest in the sky, was rising in the low north eastern sky.  This star is a beautiful shade of red/orange.

Capella about to be eclipsed by powerlines. 250mm, 4sec, f/5.6, ISO 6400

• The Double Cluster in Perseus and M31 were clearly visible to the naked eye in the northeast during observation. I've been using M31, in particular, as a benchmark for brightness comparison with the dimming comet. These celestial objects are conveniently situated around the W asterism of Cassiopeia. The Double Cluster presents an astonishing view through binoculars due to its size, luminosity, and star density.

Double Cluster in Perseus, 75mm, 6.2sec, f/4.0, ISO 6400

Nov 10

• The comet, reported to have a magnitude of 7.6, was expected to be located in the sky roughly halfway between IC 4665 and Altair. Upon arrival, Ed and I immediately surveyed this region with our binoculars. Ed believed he spotted a comet, but I did not see it. Soon after, a thin layer of clouds obscured the area where the comet was anticipated to be. I attempted to photograph the region, but the bright gibbous moon cast distinct shadows on the ground, and the clouds interfered, preventing confirmation of the comet through binoculars or in the images.

Area of sky where comet is reported, through a thin layer of clouds. 75mm, 8sec, f/4.0, IS0 400